$A$ circular coil of mean radius $7 \, cm$ and having $4000$ turns is rotated at the rate of $1800$ revolutions per minute in the earth's magnetic field $(B = 0.5 \, \text{gauss})$. The maximum $e.m.f.$ induced in the coil will be .... $V$.

$A$ coil having $1000$ turns and an area of $0.10 \ m^2$ rotates at half a revolution per second and is placed in a uniform magnetic field of $0.01 \ T$ perpendicular to the axis of rotation of the coil. The maximum emf voltage generated in the coil is . . . . . . $V$.

$A$ circular coil of radius $10\, cm$ is placed in a uniform magnetic field of $3.0 \times 10^{-5}\, T$ with its plane perpendicular to the field initially. It is rotated at a constant angular speed about an axis along the diameter of the coil and perpendicular to the magnetic field so that it undergoes half a rotation in $0.2\, s$. The maximum value of $EMF$ induced (in $\mu V$) in the coil will be close to the integer $....\mu V$.

$A$ ring of resistance $10 \Omega$,radius $10 \text{ cm}$,and $100$ turns is rotated at a rate of $100$ revolutions per second about a fixed axis which is perpendicular to a uniform magnetic field of induction $10 \text{ mT}$. The amplitude of the current in the loop will be nearly $A$ (Take $\pi^2 = 10$).

When a wire loop is rotated in a magnetic field,the direction of induced $emf$ changes in every

In a region of uniform magnetic induction $B = 10^{-2} \, T$,a circular coil of radius $r = 30 \, cm$ and resistance $R = \pi^2 \, \Omega$ is rotated about an axis which is perpendicular to the direction of $B$ and which forms a diameter of the coil. If the coil rotates at $200 \, rpm$,the amplitude of the alternating current induced in the coil is.....$mA$.